Rheumatoid arthritis pharmacotherapy and predictors of disease-modifying anti-rheumatic drug initiation in the early years of biologic use in Quebec, Canada.

Disease-modifying anti-rheumatic drugs (DMARDs) are the cornerstone of rheumatoid arthritis (RA) pharmacotherapy and should be initiated promptly after RA diagnosis. We examined trends in use of traditional and biologic DMARDs, and non-DMARD treatments, among overall RA patients, and factors associated with DMARD initiation in the newly diagnosed RA. RA subjects identified with the Quebec administrative databases were followed between January 1, 2002, and December 31, 2008. DMARD use was characterized on November 1 of each year using cross-sectional analyses. For a subgroup of newly diagnosed subjects, we used multivariable logistic regressions to identify predictors of DMARD initiation within 12 months of diagnosis and survival analyses to appraise time to DMARD initiation. A total of 37,399 subjects were included (65.8 % ≥65 years; 70.5 % female). The percentage of subjects using any DMARDs increased over the study period from 41.4 % [95 % confidence interval (CI) 40.8-42.0] to 43.3 % (95 % CI 42.7-43.9). Among newly diagnosed RA, being followed by a rheumatologist was the strongest predictor of DMARD initiation (odds ratio 4.31; 95 % CI 3.73-4.97). Care by an internist, increasing calendar year, use of NSAIDs, corticosteroids, or opioids, and a history of hospitalization increased the likelihood of DMARD initiation. Older age, female, higher comorbidity score, number of medical visits pre-diagnosis, care by other specialists, and the use of acetaminophen were inversely associated with DMARD initiation. The probability of any DMARD initiation at 12 months was 38.5 %. Despite the clinical practice guideline recommendations for earlier aggressive RA management, DMARD use appears to be suboptimal in Quebec.